You can determine a position from the
space of minutes will carry the modern aviator
record of a previously kno~w position,
many miles off course.
course, speed, and time traveled by what
During the early days of aviation, direction
of flight was determined within the aircraft chiefly
by direct-reading magnetic compasses. Today the
direct-reading magnetic compass still finds use as
a standby compass should the more sophisticated
Q12. What navigation system makes use of the
compass systems fail.
physical laws of motion that Newton
described three centuries ago?
COMPASS SYSTEM SENSORS
In chapter 6, the heading indicator is
mentioned as a flight instrument. This instrument
AIRCRAFT COMPASS SYSTEMS
is part of the primary heading reference system.
The heading indicator receives electrical/electronic
Learning Objective: Recognize the
signals from various components in the system
operating principles and features of com-
and shows the pilot aircraft heading in degrees.
pass systems, the attitude reference system,
Do not confuse this compass system with the
and associated sensors and indicators.
standby compass system (wet compass) covered
Countless navigational devices and methods
in chapter 6.
have been invented and devised. In the present
Sophisticated navigation systems and weapons
era, with its supersonic speeds, accurate deter-
delivery systems require aircraft heading informa-
mination of direction has become increasingly
tion in electrical/electronic signal form. In
important. An error of only a few degrees in a
this form, the information goes to computers,
Figure 7-12.--Flux valve heading changes.